These days, in a mobile communication system, a band of a transmission band is being widened as demands for large capacity communication are increased, and a shortage of an available radio frequency resource becomes a problem accordingly. In order to improve frequency use efficiency with a limited radio frequency resource, increasing communication capacity by an MIMO (Multiple-Input Multiple-Output) transmission technology is regarded as being effective, but there is a limit on increase in the number of antennas due to a problem of an apparatus scale.
Thus, for example, it has been considered in NPL 1 etc., that in addition to a conventional cellular system in which a cell is formed so that each of macro base stations with the same scale covers different communication areas, by newly arranging a pico base station having a communication area smaller than that of the macro base station in a cell to form a new cell, it is sought to subdivide a′ communication area per base station to increase communication capacity (hereinafter, a cell formed by the macro base station is referred to as a macro cell, and a cell formed by the pico base station is referred to as a small cell). As one example, in a case where a lot of terminal apparatuses exist in a macro cell in which a small cell is formed, the macro base station instructs a terminal apparatus which is positioned in the small cell to connect with the pico base station. By connecting the terminal apparatus which has received the instruction with the pico base station, a load imposed on the macro base station is able to be offloaded to the pico base station, resulting that transmission opportunities of all terminal apparatuses in the macro cell are able to be increased.
In the cellular system, typically, capability of a power amplifier is limited in a terminal apparatus which is desired to be downsized. Therefore, in uplink, a transmission scheme of a transmit signal is desired to have a PAPR (Peak to Average Power Ratio) as low as possible in order to seek linear amplification with high efficiency. In the LTE-A (Long Term Evolution-Advanced) standard which is actually specified these days, DFT-S-OFDM (Discrete Fourier Transform Spread Orthogonal Frequency Division Multiplexing; also referred to as SC-FDMA (Single Carrier Frequency Division Multiple Access)) and Clustered DFT-S-OFDM based on single carrier transmission having excellent PAPR performances are employed as the transmission scheme of the uplink.